


One Should Listen From Time To Time

by Nakuro



Category: Undertale (Video Game)
Language: English
Status: Completed
Published: 2019-04-02
Updated: 2019-09-27
Packaged: 2019-12-31 22:45:06
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 5,220
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18323477
Author URL: https://archiveofourown.org/users/Nakuro/pseuds/Nakuro
Summary: Sans knew he should have listened to Red, to Papyrus, to damn near everyone. But it was a little late for that now wasn’t it? Talk about embarrassing.





	1. Chapter 1

One Should Listen From Time To Time  
By Nakuro  
Summary: Sans knew he should have listened to Red, to Papyrus, to damn near everyone. But it was a little late for that now wasn’t it? Talk about embarrassing.

Sans sighed as he looked at the sky outside the window of his room. He was going stir crazy. Ever since Red had found out they were having a kid, he and Papyrus both had been treating him like he was a baby bones and he was sick of it. He was a grown man. He could make his own choices. And one of those choices meant if he wanted to go to the fucking lab he would damn well go to the fucking lab. Practice contractions be damned. But of course Red was not ok with that. Of course he was being an idiot and stupid, and yadda, yadda, yadda. 

If Sans was in Red’s position he might have agreed with him. But he had been trapped in the house by everyone under the stars for going on 7 months now. So what if he was 8 ½ months into this endeavor. He had been under house arrest for what felt like ever. And now Alphys thank the stars had offered him an out and he planned on taking it. Alphys needed help with the C.O.R.E. and since Gaster was the one who had made the damn thing he was the only one that remembered anything about it. Not that anyone but him remembered his Gaster, but still. 

He had an out and he planned on taking it. Milking it for every last drop he could. But first he had to talk Red down which was proving harder than he thought. But he was unwilling to give up. He was going to the lab no matter what. Even if he had to take his heavy ass out the window on a rope made of sheets he would at this rate. 

“Sans, no. You are staying here until the babybones is born.” Red snapped at his unreasonable soulmate. 

“Oh yes, good. And while I do that we let the whole underground blow up.” Sans snapped back. Yes he was being a wee bit over dramatic, that would only happen if he didn’t tend to it for 5 more months but he wasn’t going to tell Red that. “Big huge explosion, right over a huge reservoir of lava in a dormant volcano, what could possibly go wrong?” 

“Sans, it’s not going to happen in the next two days or so, look I know you’re stir crazy, I understand that.” Red told him and Sans mentally growled. 

“Understand the back of my hand bitch.” But he held his tongue, even when mad beyond belief he didn’t want to say something that would actually hurt Red’s feelings. 

“But you are so close to delivery now walking there, let alone teleporting there would be a huge risk to you and the babybones.” Red told him and yes Sans knew this. “Just wait a few more days until the babybones is born and then you can go fiddle with the C.O.R.E. to your soul’s content.” 

“No. Red I’m going and you can’t stop me.” Sans put his foot down. “Now either you get out of my way and I walk or so help me I’ll teleport.” 

Red sighed but crossed his arms. “No Sans. you’re staying right here.” 

Sans turned in that very second and even slowed down some by the added weight he was still faster than Red, before Red could grab him he had teleported himself outside the lab. It wasn’t flawless and he had to lose some of his lunch in a nearby bush after, but he had made it. At least for the time now he was safe from the room and from Red. Though the skeleton was no doubt on his way to find him right now. He didn’t have much time. 

He knocked on the lab door and after hearing some scurring and fighting through another painful practice cramp the door opened to reveal the nervous lizard. “Heya Alph. What’s goin’ on with the core?” No need to worry Alphys. 

“Heya Sans.” Alph smiled before leading him to the C.O.R.E. “I don’t really know what happened but the readout wasn’t showing proper levels.” 

“Yeah we need to refill it’s “oil” reserves.” Sans voiced up after taking a look at the readout. “No big deal. Problem is… I don’t exactly remember what the chemical combination was.” 

“You WHAT?” Alph yelled at him before taking a deep breath. “Ok, fine. Do you at least remember the elements?” 

“Yes. Well two of them at least. The third is iffy.” Sans confessed honestly but now he was starting to feel the sweat on his skull. He needed to go fast. 

Alphys sighed loudly before sitting Sans down and talking over the possible element combinations. After five failed experiments Sans was really feeling the magic in his soul going haywire, and that couldn’t be good. Still he could fake it. It was fine. He was fine. 

“Thanks again for taking your time to help out.” Alphys told Sans after looking over the papers. 

Sans sighed softly, this was definitely painful. Not to the point he couldn’t see but it was definitely worrisome. Was he in labor already? If so he couldn’t teleport home. It would force him into the void and into birth much faster. Maybe if he focused on it and slowing it down, he could make it wait until he got home. 

“No prob bob.” Sans sighed softly. “Hnnn.” He groaned softly biting back a scream. 

That one hurt more than the others and even his magic tried to react at that point. This was really really not good. He’d have to call Red. He’d have to hear all about how stupid he was and why he thought it was a good idea in the first place. He was not ready for that. Though to be fair he wasn’t ready for the birth either. The whole time the babybones was growing in him he wanted to birth them so he could see them, now that he was actually in the thick of it, he just wanted to skip it. 

“Okay… So we need a substitute to add to the chemicals...” Alphys mumbled to herself in thought. 

“A-Aah!” Sans couldn’t have kept that cry silent if he tried. The contraction took hold in earnest, his soul pulsed with pain, then magic flooded into his magic belly to force liquid out quickly and in a rush. Shit. Labor was definitely starting now. 

“Bleach caused it to explode-” Alphys started but Sans had to interrupt her. 

“Water!” He voiced up which wasn’t usually like him to speak loudly. 

“W-Water?” Alphys couldn’t understand why water would be the substitute to use. 

“Broke...” Sans winced out as he squeezed Alphys’ shoulder. He was so lost in pain right now he didn’t care if Alphys didn’t like touch. 

Alphys sat there for a minute, processing what Sans had said. Water, then broke. Sans was pregnant meaning… When it finally clicked her eyes could only widen in shock and she screamed in just as much shock. Strange as it was, seeing Alphys freak out helped Sans to be calm. He wasn’t taking this as badly as she was. It was something. When the pain stopped he grabbed his phone and quickly called Red. Red had been grumbling at the TV since Sans had teleported away. He just wanted them safe, that was all, and somehow that made him the bad guy. When his phone rang he debated letting it go to voicemail, he really couldn’t take much more today. But Sans might need him and he couldn’t ignore Sans so he bit back his anger and answered in his lazy tone. 

“’Ello?” Red growled when Sans didn’t instantly answer. “’Ello?!” He couldn’t help it his rage entered his voice. 

“L-Lab.” Sans gasped out through another contraction, he knew he had to push but he couldn’t talk on the phone and push at the same time. God he wanted this to be over already. “B-Baby b-bones!” 

Red dropped the phone, scrambling to pick it up his rage was gone for the moment. “Sans! What about the babybones?!” 

“C-C-Commiiiiiiiing!” Sans howled in pain before his hand holding the phone moved to grip his magic belly, that contraction hurt and his body was now forcing him to push. 

“Sans! Sans I’m coming. Stay there.” Red hung up grabbed the babybones’ bag they had made over the months and teleported to the lab. 

As if I could move. Sans thought to himself before hanging up and focusing on his breathing. He could do this. Red was on his way, soon he would be a dad and this would all be a bad memory. However as he felt another contraction and pushed through it he felt tears spring to his eye sockets. Fuck this was painful. 

“Sans!” Hearing Red made Sans relax some. “Sans, oh god, Fuck. Sans you couldn’t have waited?” The glare Red received was deserved and he shrunk back a bit at it. “Y-Yeah. Wrong time. I hear ya.” He grabbed Sans’ hand and held it as he fought his way through another contraction. 

He had saved up his magic for this day and was glad he had. Sans had teleported which had used up a lot of the magic he needed for the birth. They would both be tired after this. Sans cried out in pain and Red felt the tug on his soul. Now was the time. Red let his magic form and moved to gently touch his magic belly. 

“R-Red please. Just make it end.” Sans groaned out hating this whole thing already. 

“Shhhh. Just focus ok? One, two, three.” Red counted and on three Sans did as he had been training, took a deep breath and pushed, his hip bones already moving to make room for the babybones to come out. 

“Aaaaah!” Sans yelped and clung to Red. He’d gone through genocide routes before and that hadn’t hurt as much as this. He was going to dust. That’s all there was to it. 

“Well done Sans.” Red winced out. Pain. Something he understood far more than others of his kind. “Take a breather for a second.” 

Thankfully the screaming of Alphys had stopped at this point and she had scrambled over to Sans. “H-H-How can I h-h-help?” 

Red hated stuttering but there was no way that Toriel would get here in time to help. The babybones was already starting to crown, they were out of time. “Towels, do you have any?” He was on his own in this. 

“T-Towels? Uuuuh I think s-s-so.” Alphys replied she had been and always was nervous around people that were intimidating and Red was most definitely that. 

“Then go fucking get them!” Red snapped and Alphys flinched like she had been hit, meanwhile Red flinched from Sans squeezing his femur with more strength than he thought possible. 

“P-Please go get them. Nnnnnngh.” Sans smiled before wincing hard as he pushed again this time fighting back a scream of pain as he felt like he was being torn in half, even with Red supplying some magic of his own. 

“R-R-Right away!” And Alphys dashed off as fast as she could to look for towels. 

“Now’s really not the time fer-” Red was cut off as Sans slapped him. 

Sans wasn’t one for L.O.V.E., so normally “slaps” were a tap, but this one was a real slap. “D-Don’t be mean toooooh ow. To her just cause she’s nervous.” Sans ordered and Red lowered his skull. 

He knew Sans was right and it was so like him to correct his behavior even when he was having the worst pain of his life. He screamed which brought Red back to the real world. He could only watch in both pride and shock when he saw the head of their babybones, free itself from Sans’ pelvis. They were being born, they were really here, this was really happening. 

“I found the towels oooof!” Alphys cried out as she ran towards them, tripping over her claws and crashing hard to the ground. She got up slowly and gingerly held the towels to Red. 

Red took them without a word, now that the reality was hitting him he didn’t bother keeping up his attitude. “I need water. Stat.” 

“R-Right.” It gave Alphys something to focus on and she turned to handle it. 

“Slow.” Red reminded her in his guard tone from back when he was a royal guard too. 

“Y-Y-Yes sir.” Alphys ran off to go get some water and remember Red’s order. Slowly. 

“I can’t do this.” Sans groaned out in pain, he was already exhausted and relying only on Red’s magic now, his reserves had all been used. 

“You can and you are.” Red told him calmly laying a towel where it was obvious Sans’ water had broken and putting the other under Sans’ hip bones gently. “Just a few more pushes and we’re a family.” 

“I… can’t.” Sans whined but with the next contraction he gripped onto Red’s magic with his soul and pushed hard. 

Red grunted one of his own eye sockets closing in the pain he felt but when Sans fell back exhausted he smiled, the first shoulder was out. Two more pushes and Sans might be able to rest. “Come on Sans, you can do this. You’re almost there.” He looked Sans in the eye sockets and when he noticed the slight twinge voiced up. “Push!” 

Alphys was walking up the hallway when she heard Sans scream then fall silent only to be replaced with another louder scream seconds later. She walked a little faster until she came over to see Sans who had been pants somehow before now, likely he did it himself and she didn’t notice because she was freaking out, and there Red was sitting between Sans’ legs holding a baby skeleton covered in blue magic. 

“Awwwe.” Alphys handed the water bottles to Red who opened one to quickly wipe off the screaming babybones. “Their so cute.” 

Red felt pride swell in his soul at hearing that. They really were so cute. “Sans?” Sans made a weak sound something between a hnn and yes. “You want to hold them while I call Toriel?” 

“Sure.” Sans’ voice was horse and strained and Alphys had no doubt as to why. 

Red backed up after handing their child to Sans to hold as he fished his phone out of his pocket and dialed the number turning away for just a minute until he was sure Toriel had picked up. 

“Hello my child. How is Sans?” Toriel’s singsong voice came through the phone and Red turned back around to face Sans and their baby bones feeling strangely safe with Alphys gushing over the newborn next to Sans. 

“He’s ok now, but if ya have da time, I would really appreciate it if you came to check on the babybones.” Red told her his pride no doubt entering his voice. 

“Why? Did something happen?” Toriel asked in a worried tone. 

“Yeah. He had the kid.” Red confessed and chuckled as he watched Sans joke around with Alphys. 

“I’ll be right there.” Toriel told Red in a hurried rushed tone. 

“Please… take your time.” Red never would have thought in a million years he would feel safe with someone he didn’t know much about near his soulmate and child but he did. “Their ok where they are right now.” Toriel hung up and he walked over to his family. He wasn’t such a disgrace now, was he?


	2. Part 2

Sans sat and held Noto Mono their son. He had grown from a newborn to a toddler and was as lazy as both his parents were, which made things for the parents easy. They appreciated that. Thankfully Red’s difficult self didn’t seem to get into Noto. Sure he was as stubborn as a mule but they were both that, so there was no chance he wouldn’t be too. It had been a good five years with Noto and Red and Sans loved him very much. But they wanted more. At first Sans was against trying to add more children to their family because he remembered how much the first one hurt. But over the years even he wanted to try again. Even he wanted to have another child. So they agreed to try again. For three years they had been trying and for three years they had been disappointed.

So they had given up, they would half halfheartedly try whenever they were both in heat but neither of them expected that it would happen anymore. It made Sans depressed a lot of the time thinking he couldn’t give Red the one thing they both wanted. That he was failure. That he could only give them the one child. Not that he didn’t love Noto, he did, but he wanted to give Red what he wanted too. Sans was yanked from his thoughts when Noto grabbed his hand.

“Hm? What is it baby bones?” He asked as he saw the little one climb up on his lap.

“What is Pregnancy?” Noto asked and Sans chuckled.

No doubt Noto had heard him talk about it when he was talking to Red. “It means that Papa here would have magic right here.” He pointed to his belly. “Where another little babybones would grow so that we could then meet them like we did you.”

Noto blinked at Sans’ belly. “So there’s a new member in there now?”

“No.” Sans replied sadly. “Daddy and I are trying little one but trying doesn’t always mean you succeed.”

Noto frowned until he heard the keys in the lock of the door and dashed towards it. “Daddy!” He cried out as Red came home.

He closed the door, chuckled and picked Noto up. “How’s my little muffin?” He chuckled lightly.

Sans smiled and rose to his feet. “Noto has been asking about pregnancy.” He told Red.

Red looked at Sans his smile faltering for second before he replaced it so as not to worry Noto. He knew Sans felt bad about not being able to conceive. He knew it bothered him a lot more than he would admit. He had faith if it was meant to happen again it would.

“Well our little ankle biter is growing up.” Red teased before putting Noto down so he could go run off and get what he wanted to show Red like he did every day, before turning to Sans. “It’ll happen if it’s meant to happen Sans.” He hugged Sans tightly. “Stop trying so hard and just enjoy what life has given you already.”

Sans smiled and knew that Red was right. He was getting so focused on trying that he was upset when it didn’t work. And magic was a reflection of the monster’s soul so it made sense. So for the next year, sure they’d try every heat but Sans stopped taking the tests. They gave him nerves and depression if it was a no, so he ignored them. Even when he felt a little flu like he ignored them. His mind was playing tricks on him. Trying to get his hopes up. He wouldn’t fall for it. So he kept going even playing with Noto and going to amusement parks. The only time he really started to pull the breaks on his mind and reconsider if he was pregnant was when one day he vomited every time he lifted anything with his magic. Even Noto. It was only then that he took a step back, set Noto up to play with something for a minute and went to the bathroom.

“Come on Sans. Get your skull on straight.” He pulled up his shirt to look at his belly. “There’s nothing there.”

He let the breath that he had been holding out as he looked at his belly. It wasn’t faint like he expected but it wasn’t a strong glow either. Though his tummy was definitely there. Nope. His mind was just trying to make him happy. It wasn’t true. Still to cover all his bases he pulled out his phone and texted Red.

“Hey honey. Do me a favor and pick up some monster pregnancy tests on the way home.”

The reply was almost instant. “Are you sure? You said they made you anxious.”

“Yeah I’m sure.” Sans replied with a sigh. “I’m not feeling to good and want to rule out possible causes for concern.”

“Ok Sweetheart.” Red replied with a smile emoji and Sans chuckled before returning to their son.

He was such a goof. Sans played with Noto for a few more hours before getting him dinner and putting him to bed. Red must have had to stay late so Sans was on his own for the first little bit of nighttime with Noto. Not that he minded. He knew Red loved his job and since he had their son he didn’t mind watching over Noto all the time. When Red came home he looked exhausted but he held up the pregnancy test box like he had fought a war to bring it home. Sans chuckled as he walked over to Red and kissed him.

“Thanks honey. I’m going to go take this now.” Sans told Red before motioning to the plate of food he had made for his dinner.

“Thanks.” Red smiled as they parted ways for the moment.

Red to eat his dinner and Sans to take his test. He took a deep breath and told himself a few dozen times that even if it said no that was ok, that it could still happen in the future and he was just sick. He opened all the tests then took each one and while he was pulling up his shorts he happened to glance at them almost not believing what he saw. All three had only been set down for a third of the time needed for an answer and yet they all had the reading of positive.

“No fucking way.” Sans yelped out in shock as realization finally hit him.

Red dashed in hearing Sans curse, his mate never cursed if he could help it. “What?!” He looked over at Sans to see him crying. “Fuck I knew these tests were a bad idea.” He went to grab them and throw them away when he saw Sans grab his hand. “Sweetheart this-”

“Look.” Sans told him interrupting his comforting words. “Read them Red. Read them.”

Red looked at Sans confused raising an eyebrow ridge before taking a look at the tests in his hand. An actual look. All three said positive, and only then did his eye lights flicker out only to return as he looked at Sans almost not believing what he was seeing.

“You mean...” Red gulped as Sans lifted his shirt to show the light blue belly that lay there, the belly that was growing their second child. “Come here.” He forgot the tests and kissed Sans.

He held him close and kissed him over and over again to show how happy he was. Sure he knew it would be difficult and that he would have to work on some of the checks… Hey wait. Why did they need to go to the doctor at all? They had done this before, there’s no reason they couldn’t do it again all by themselves. Red pulled back for a second to look Sans in the eyes.

“Hey. Why don’t we do unassisted?” Red asked and Sans’ face lit up.

“You mean it?” He asked.

“Of course. We did it once, there’s no reason we can’t do it again.”

Sans smiled at Red and held him in a hug. He was so excited and he knew Noto would be too. Red smiled and rubbed Sans’ back.

“I told you it would happen again.” He chuckled out.

“Heh. Yeah I guess so.” Sans smiled back.

More than anything Sans was so happy that even going through the mood swings, and morning sickness, and everything else was something he enjoyed. He enjoyed being pregnant now and he enjoyed the wait but as with everything, eventually the waiting ends. Sans was taking a nap when he felt the first of many contractions. He grunted and winced fighting back tears. Noto had had trouble sleeping because of the storm so he was in the bed with him. It was seeing his Papa in so much pain that caused him to start crying.

“Oh no no. Noto, honey bear it’s ok.” Sans wiped the tears from Noto’s face. “You’re going to be a big brother soon.” He told him before gripping his large belly and wincing again.

This caused Noto to sob and cling to Sans for a good hour or so. Now he had to fight through the contractions, trying to stay silent while also trying hard to calm Noto. Eventually sleep claimed their son, happily, and he pulled his hand away to stand up and ensuring that Noto was still asleep headed for his cell phone to then walk out of the room to call Red hoping to not disturb Noto.

“Hello?” Red picked up after the second ring.

“Red.” Great even his voice was shaking. “The babybones is coming.” At least he sounded stronger this time than last time.

“How close are the contractions?” Red asked as he headed up towards his boss in the elevator to say that he had to go, his mate was in labor.

Sans looked at the clock and it took him a minute to read it with how tired he was. “F-Five minutes. Oooooooh.” He groaned as he gripped the stair railing with all his might. “Make that f-four.” Sans heard Red talking hastily to his boss before hearing a door close.

“I’m on my way. Just wait a few minutes.” Red told him before hanging up and teleporting into the house at the front door. “Where’s Noto?”

Sans glanced at the door to their room. “He’s asleep.”

Red nodded and letting Sans use him as support took them into the bathroom to try laboring in the tub for a while. It let Sans relax some which he was grateful for. Red rubbed his arms.

“You’re doing so well sweetheart.”

Sans smiled and then weakly spoke. “Sorry about dragging you away from work. Nnnnnngh!” He gripped the side of the tub and tried to crawl out but this contraction held him tight and wouldn’t let go.

Before Red could really help Sans relax after the contraction Sans spoke again. “S-Something’s wrong.” He winced and once again barely screamed having been more prepared for the pain this time he hadn’t felt the need to but this time he had to.

Red took the info in and removed Sans’ shorts and shirt before looking at the belly of magic. Shit. Their newborn was coming down butt first. Sometimes humans could have breech babies and be ok but skeletons and magic were a whole different story.

“Sans stop.” Sans looked at Red hearing a voice he had never heard before come from him, it sounded strong but terrified. “It’s breech. I have to turn it.”

Sans’ eyes went wide, turning a babybones while still in the belly was one of the most painful things about monster skeleton births. Since everything in a skeleton birth was magic there was nothing to stop them from feeling every movement during the turning.

“F-Fuck.” He cursed before throwing his skull back and gripping the tub tightly. “O-Ok.”

Getting the ok Red put his hands in the water and slowly up Sans’ sensitive tunnel which caused him to grunt in pain. Gently grabbing their newborn he started to turn them the right way and as he did so he heard Sans scream louder and in more pain than he had ever heard him scream. The scream caused by the turning also started making him sob. But their little one was in the right position now.

“Sweetheart I’m so sorry.” Red wiped Sans’ eye sockets of the tears and Sans just tried to focus on the task at hand. Everything about him was burning right now.

“Papa?” Noto asked as he opened the door sobbing.

“Noto.” Red mentioned looking at their son before getting up to pick him up. “Papa’s here. Papa’s fine.” He brought Noto over to Sans who gently pet Noto’s skull.

“Heya short stuff.” He teased as best he could. “Papa’s going to be ok but he might scream and cry ok? It’s just part of what he’s going through. I’m ok.”

Noto took in what Sans said before he saw his Papa wince and move to do something then start crying and grunting. “Papa!”

Red glanced over at Noto. “Papa needs quiet right now Noto ok?

Noto sniffed but nodded and carefully sat next to the tub out of the way.

“Ok Sweetheart, good job, now push. Push hard.” Red knew that after a babybones was turned there was no going back. This was their last child ever. All because of his stupid luck.

Sans took a deep breath and did as he was told screaming in pain as he felt his now oversensitive magic stretch hard and fast. He couldn’t stop the tears from falling even as he knew he was doing everything right.

“I just HAD to have another.” He grumbled to himself before he took a deep breath and pushed again.

Once again the push was excruciating, and he felt like he was dusting each second but then he heard something splash and looked down to find his water had finally broken. They were getting close at least. Noto left the room unable to watch his Papa like that and walked around downstairs.

“You’re doing great Sweetheart just breathe.” Red told Sans gently.

“I… I’m trying Red.” Sans panted out before he took a deep breath and pushed hard this time he felt the pain up in ante but after screaming he waited for the next contraction and pushed hard panting as the pain dulled down some.

He panted took a moment to regain his will then pushed again this time he felt their newborn slide out and Red started getting them to cry. It didn’t take long, and soon the little skeleton was screaming loudly. Red chuckled and handed her to Sans who held her close. Noto hearing a different scream came back into the room.

“Papa?” He asked and Red smiled before standing up and giving Noto some room.

“Hey Noto. Come meet your sister Lucida.” Sans told Noto as he smiled at Red.

Red smiled back watching as Noto looked at the new baby skeleton and laughed, bouncing a bit in his eagerness. Sans for his part tried to relax. His bones hurt and he started to feel very weak.

“Red.” His voice was almost gone but thankfully Red heard him and took their newborn from his arms mere seconds before Classic would have dropped her. “Thanks.” Red nodded and sat down on the ground to let Noto get a better look at Lucida. 


End file.
